1. Field of the Invention
One or more embodiments of the present invention generally relate to seismic data processing, and more particularly to estimating absorption parameter Q.
2. Description of the Related Art
Absorption parameter Q, which may also be referred to as anelastic attenuation or seismic quality factor, has considerable impact on surface seismic reflection data. For example, preferential attenuation of high frequencies generally increases the dominant signal wavelength and period, which therefore degrades resolution. Quantitative analysis of amplitudes is commonly complicated by absorption parameter Q during amplitude variation with offset (AVO) analysis where attenuation effects are superimposed on AVO signatures. If accurate values of absorption parameter Q are known, these difficulties can be corrected. Furthermore, absorption parameter Q is a useful parameter in its own right because it is sensitive to parameters such as lithology, porosity, and pore fluid characteristics.
Accordingly, knowledge of Q is very desirable; however, it is rarely measured. Many laboratory-based measurements of Q and its dependence on parameters such as lithology and gas saturation have been made on core samples. Unfortunately, these measurements are made using kilohertz-range seismic signals at a limited range of ambient pressure and temperature. As a result, these laboratory laboratory-based measurements, when compared to in-situ conditions, may be questionable or ambiguous.
Therefore, a need exists in the art for an improved method for generating an estimated value of absorption parameter Q.